<!DOCTYPE html>
<html lang="ch-CN">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>边框</title>
    <style>
        .one {
            /* 边框：独占一行 */

            /* 边框宽度 */
            border-width: 3px;  
            /* 边框颜色 */
            border-color: blue;
            /* 边框样式:solid->实线 dashed->虚线  */
            border-style: solid;
        }

        .two {
            /* 可以这么简写:宽度-颜色-样式 */
            border: 2px blue solid;

            /* 行高: */
            line-height: 50px;
            /* 如果没跟单位px 如line-height: 5 -》表示的就是 */
        }

        .three {
            /* 局部边框 */
            border-bottom: 2px blue solid;
            border-left: 3px blue solid;
            border-top: 2px blue dashed;
            border-right: 5px blue solid;
        }
    </style>
</head>
<body>
    <p class="one">1床前明月光,疑是地上霜</p>
    <p class="two">2举头望明月,低头思故乡</p>
    <p class="three">2举头望明月,低头思故乡</p>
</body>
</html>